Technical Bleeding brakes!

[digger58]

Having trouble getting a pedal after new rear shoes and wheel cylinders+ strip of calipers with new seals. let gravity bring fluid to all bleed nipples to start with but no joy. Any ideas please?

 

[corcai]

Are the adjusters in the rear brakes adjusted correctly?
- adjust out until the shoes are grabbing
- then I pull the handbrake to center the shoes with the drum
- adjust again if necessary until shoes are grabbing
- then back off adjuster 10 teeth I think is Fiat recommendation

Is the pedal spongy, or does it go slowly to the floor.

Master cylinder seals can be damaged by pumping the full travel as the part of the bore not normally swept can be lipped or rusty.

 

[digger58]

Hi Corcai, pedal creeping, I suspect that the seals are damaged, I did all the adjustment bit, freed out the adjusters and put graphite dust on the threads etc, I thought I had been careful enough with the pedal but obviously not. Judging by the state of the wheel cylinders the fluid was old and full of moisture. A pipe had been changed so some new fluid but in the calipers and wheel cylinders there was a lot of muck. Suppose same in master cylinder. I'll treat it to a new one anyway, I prefer to do a job right especially when I go "far far away" on my trips.

 

[digger58]

New master cylinder fitted today, creeping pedal has gone but still finding it difficult to get a decent pedal.The old one was very gunky inside with a nice brown sludge. Lot of moisture in the reservoir. Doubt the fluid was ever fully changed. Any tips on getting a decent pedal please ?

 

[errolmorris]

Since you have a new master cylinder, do a full pedal bleed if you have an off-sider to help. Make sure you have plenty of spare fluid whilst bleeding.
The only other option would be a gravity bleed, which if you are on your own, will take a little time but still less time than organising a funeral...and certainly more economical.
From your description, it sounds like a gravity bleed might not be that good a solution as you will need to pump any left over gunk out of the lines.

 

[digger58]

Eventually got it bled! a real b..ch of a job, 2 of u for nearly 3 hrs, pressurised kit and pumping pedal! Nice brakes now at least.

 

[errolmorris]

Congrats.